KR100541966B1 - Millimeter wave band amplifying apparatus and matching circuit - Google Patents

Abstract

The present invention relates to a millimeter wave band amplifier and a matching circuit. In particular, a matching circuit is constructed using a microstrip line and an open stub, and capacitors are used in the input matching circuits of each stage to have gain components in a desired operating frequency band and attenuate gain components in an unwanted frequency band. A millimeter wave band amplification device and a matching circuit used therein.

Amplifiers, millimeter waves, matching circiuts, and capacitors.

Description

Millimeter wave band amplifying apparatus and matching circuit             

1 is a circuit diagram of a millimeter wave band amplifying apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating gain and input / output characteristics of the amplifier shown in FIG. 1.

The present invention relates to a millimeter wave band amplifier and a matching circuit. In particular, a matching circuit is constructed by using a micro strip line and an open stub, and a capacitor is used in an input matching circuit of each stage to have a gain component only in a desired operating frequency band and an unwanted frequency band. The present invention relates to a millimeter wave band amplification device capable of attenuating the gain component in the circuit and a matching circuit used therein.

Conventional millimeter wave band amplification apparatus has a high gain in the low frequency band due to the characteristics of the device, and also implies that oscillation in the low frequency band always occurs due to modeling limitations. In addition, in the conventional amplification apparatus, a matching circuit is formed for gain components and input / output reflection characteristics using only microstrip lines and open stubs, which are distributed elements, but this attenuates gain components outside the operating frequency band. There is a problem that requires a lot of time for the designer to obtain excellent input and output matching characteristics.

Accordingly, the present invention is to solve the above-mentioned problems of the prior art, and to configure a matching circuit using a microstrip line and an open stub, and to gain only in a desired operating frequency band by using a capacitor in the input matching circuit of each stage. It is an object of the present invention to provide a millimeter wave band amplification device and a matching circuit used therein, which are capable of attenuating gain components in an unwanted frequency band and easily designing an input / output matching circuit.

As a technical means for achieving the above object, a first aspect of the present invention is an open stub connected between a first microstrip line, a capacitor, a second microstrip line connected in series and between the capacitor and the second microstrip line. It provides an input matching circuit comprising a.

A second aspect of the present invention provides an output matching circuit connected to an output terminal of a first amplifier, a DC blocking capacitor connected in series to the output matching circuit, and a DC stripping capacitor and a second amplifier input terminal, the microstrip line is open. An inter-stage matching circuit is provided that includes an input matching circuit including a stub and a capacitor.

A third aspect of the invention relates to an amplifier, an input matching circuit coupled to an input of the amplifier and including a microstrip line, an open stub and a capacitor, an output matching circuit coupled to an output of the amplifier, and an output matching circuit of the amplifier. An amplifying device including a DC blocking capacitor connected in series is provided.

A fourth aspect of the present invention is a first to fourth amplifier, a first to a second negative feedback circuit connected in parallel to the first to a second amplifier, respectively, and a first to fourth input matching circuit respectively connected to the input terminal of the first to fourth amplifiers First to fourth output matching circuits respectively connected to output terminals of the first to fourth amplifiers, first to fourth gate bias circuits respectively connected to T-junction microstrip lines of the first to fourth input matching circuits, and the first to fourth output matching circuits. First to fourth drain bias circuits each connected to a T-junction microstrip line of a 1 to 4 output matching circuit, a first DC blocking capacitor connected to the first input matching circuit, the first output matching circuit and the second A second DC blocking capacitor connected to an input matching circuit, a third DC blocking capacitor connected to the second output matching circuit and the third input matching circuit, the third output matching circuit, and A fourth DC blocking capacitor connected to the fourth input matching circuit, and a fourth DC blocking capacitor connected to the fourth output matching circuit, wherein at least one of the first to fourth input matching circuits is disposed on the first side. An amplifier matching circuit is provided.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, embodiments of the present invention may be modified in various forms, and the scope of the present invention should not be construed as being limited by the embodiments described below. Embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art.

1 is a circuit diagram of a millimeter wave band amplifying apparatus according to a first embodiment of the present invention. In FIG. 1, the millimeter wave band amplification apparatus includes four amplifiers 224, 225, 226, 227, two negative feedback circuits 214, 215, and four input matching circuits 216, 218, 220. , 222, 4 output matching circuits 217, 219, 221, 223, 5 DC blocking capacitors 209, 210, 211, 212, 213, 4 gate bias circuits 201, 203 205, 207, and four drain bias circuits 202, 204, 206, and 208.

The amplifiers 224, 225, 226, and 227 are power elements that increase the level of the signal, and mainly use high electron mobility transistors (HEMTs). In particular, the amplifiers 224 and 225 are used in combination with the negative feedback circuits 214 and 215 to satisfy the broadband characteristics and unconditional stability conditions.

The negative feedback circuits 214 and 215 may be composed of resistors and capacitors connected in series.

Input matching circuits 216, 218, 220, and 222 may consist of only two microstrip lines and one open stub, like the input matching circuit of 216, and three microstrip lines, like the input matching circuit of 218. And one open stub and one capacitor, and may comprise two microstrip lines, one open stub, and one capacitor, such as the input matching circuits 220 and 222. Among the microstrip lines, a microstrip line having three terminals in particular is also called a T-junction microstrip line. The input matching circuits 216, 218, 220, and 222 can transmit an input signal losslessly. In particular, the input matching circuits 218, 220, and 222 have a gain component outside the operating frequency band by using a capacitor. It is characterized in that it is designed so that it is not. Here, it is suitable for the capacitor to use a capacitor of several tens of fF for an amplifier operating in the 77 GHz band.

The output matching circuits 217, 219, 221, 223 may consist of one microstrip line and one open stub like the output matching circuits 217 and 223, and 1 as the output matching circuits 219 and 221. It can consist of two microstrip lines.

The DC blocking capacitors 209, 210, 211, 212, and 213 are configured as capacitors and perform a function of blocking DC.

The gate bias circuits 201, 203, 205, 207 and the drain bias circuits 202, 204, 206, 208 are composed of microstrip lines and capacitors.

The interstage coupling circuits 228, 229, and 230 mean circuits composed of output matching circuits 217, 219, and 221, DC blocking capacitors 210, 211, and 212, and input matching circuits 218, 220, and 222.

The millimeter wave band amplifying apparatus according to the first embodiment of the present invention configures a matching circuit using a microstrip line and an open stub as described above, and adds a capacitor to the input matching circuit at each stage, thereby providing a desired operating frequency band. Only the gain component can reduce the gain component in the unwanted frequency band, and the I / O matching circuit can be designed more easily. That is, since the microstrip line and the open stub alone are not easy to match the impedance matching of the millimeter wave band amplification device, adding a capacitor as described above makes it easy to match the impedance matching.

FIG. 2 is a diagram illustrating gain and input / output characteristics of the amplifier shown in FIG. 1.

For the measurement, a GSG type RF probe pad was used for signal input / output and a GPPPPPPG type DC probe pad was used for DC supply. Referring to the gain characteristic S21 in FIG. 2, it can be seen that there is almost no gain component outside the operating frequency band 301. In addition, it can be seen that the matching is very excellent in the operating frequency band. In addition, looking at the return loss (S11, S22), it has a value of less than -15dB in the operating frequency band, it can be seen that very excellent characteristics. Since the present invention has an operating frequency of 77 GHz band, it can be applied to a vehicle collision avoidance radar system.

Although the technical spirit of the present invention has been described in detail according to the above preferred embodiment, it should be noted that the above-described embodiment is for the purpose of description and not of limitation. In addition, it will be understood by those skilled in the art that various modifications are possible within the scope of the technical idea of the present invention.

The matching circuit of the millimeter wave band amplifying apparatus according to the present invention can design the unwanted gain characteristics and the input reflection loss characteristics in the low frequency band better than the conventional amplification apparatus using only the microstripline and the open stub. The advantage is that the design period can be shortened and the possibility of oscillation in the low frequency band can be blocked.

Therefore, the matching circuit of the millimeter wave band amplifying apparatus according to the present invention has an advantage that it can be usefully applied to the design of the ultrahigh frequency integrated circuit amplifying apparatus of the millimeter wave band.

Claims (15)

In the input matching circuit used in the monolithic IC, A first microstrip line, a capacitor and a second microstrip line connected in series; And And an open stub connected between said capacitor and said second microstrip line, said capacitor having a size of several to several tens of m 2. The method of claim 1, And the second microstrip line is a T-junction microstrip line. The method of claim 2, And a gate bias circuit is connected to the other unconnected terminal of the T-junction microstrip line. The method of claim 1, And a third microstrip line connected in series between said capacitor and said second microstrip line. In the end-to-end matching circuit used in the monolithic IC, An output matching circuit coupled to the output of the first amplifier; A DC blocking capacitor connected in series with the output matching circuit; And And an input matching circuit connected to the DC blocking capacitor and the second amplifier input, the input matching circuit including a microstrip line, an open stub, and a capacitor having a size of several to several tens of m 2. The method of claim 5, And said output matching circuit comprises a microstrip line. The method of claim 5, The output matching circuit Microstrip lines; And And an open stub connected between the microstrip line and the DC blocking capacitor. The method according to claim 6 or 7, And the microstrip line is a T-junction microstrip line. The method of claim 8, And the other unconnected terminal of the T-junction microstrip line is connected to a drain bias circuit. The method of claim 5, The input matching circuit is an input matching circuit according to any one of claims 1 to 5. In the amplification device used in monolithic IC, amplifier; An input matching circuit connected to an input of the amplifier and including a microstrip line, an open stub and a capacitor having a size of several tens to several tens of m 2; An output matching circuit coupled to the output of the amplifier; And And a DC blocking capacitor connected in series to the output matching circuit of the amplifier. The method of claim 11, And the input matching circuit is an input matching circuit according to any one of claims 1 to 5. The method of claim 11, And the amplifier is a HEMT. The method of claim 11, And an auxiliary feedback circuit connected in parallel to the amplifier. In the amplification device used in monolithic IC, First to fourth amplifiers; First to second negative feedback circuits connected in parallel to the first to second amplifiers, respectively; First to fourth input matching circuits respectively connected to input terminals of the first to fourth amplifiers; First to fourth output matching circuits respectively connected to output terminals of the first to fourth amplifiers; First to fourth gate bias circuits, each connected to a T-junction microstrip line of the first to fourth input matching circuits; First to fourth drain bias circuits, each connected to a T-junction microstrip line of the first to fourth output matching circuits; A first DC blocking capacitor connected to the first input matching circuit; A second DC blocking capacitor connected to the first output matching circuit and the second input matching circuit; A third DC blocking capacitor connected to the second output matching circuit and the third input matching circuit; A fourth DC blocking capacitor connected to the third output matching circuit and the fourth input matching circuit; And A fourth DC blocking capacitor connected to said fourth output matching circuit, At least one of the first to fourth input matching circuits is an input matching circuit according to any one of claims 1 to 5.

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